Metadata field in the Client struct

[markandpathak]

Often, hooks are mainly required to change the behaviour depending on some external data and to get the information from the server about a state. It is often required to reference external information while running hooks.

I am suggesting a Metadata field in Client struct which will be of type map[string]interface{}. Any arbitrary value can be stored in the field which gets passed along to hooks and can be used very easily.

P.S - There is a Key Value slice available in UserProperties but that can not store arbitrary data types